The present invention relates to a portable conveyor for loading and unloading products from delivery trucks.
In the delivery of general agricultural products or commodities, nowadays, conveyors are widely utilized at the production locations for loading them on delivery trucks for saving both time and labor, but these types of conveyor are generally huge in size and heavy in weight, and can not be readily carried to go by the same delivery truck to a terminal location for unloading the loads therefrom. Therefore, labor is required for unloading them when the truck arrives at the terminal location, which creates uneconomical and time consuming problems.
Conveyors for serving the above mentioned purposes are categorized into two types, and their shortcomings are described as follows:
1. Belt type conveyors.
As shown in FIG. 1A, this type of conveyor utilizes an elongated cycling, reinforced rubber belt by winding it around the front and rear end of driving rollers with a plurality of idle rollers disposed therebetween for supporting the conveyor belt, but this only increases the bulk weight of the whole conveyor to a large extent. Since the conveyor belt is made of synthetic fiber and rubber, it becomes loosely engaged due to fatigue, this in turn causes slip or poor frictional contact between the belt and the rollers surfaces, and finally resulting in the whole conveyor not functioning.
2. Flat board or thin rod type conveyors.
As shown in FIG. 1B, this type of conveyor utilizes two longitudinal parallel endless driving chains, one chain at each side, and between each pair of corresponding chain segments thereof, there are provided with multiple latitudinal flat boards or rods, as they are uniformly distributed along these two chains. Furthermore, multiple idle rollers must be provided to support the boards or rods, otherwise, the conveying surface inbetween these two driving chains will become downward curved on loading.
From the above description, it can be seen that both types of conveyors are huge in size and heavy in weight, and lack of mobility to be carried along by a truck for serving loading and unloading purpose at any locations.